Natural colors and dyes are primarily derived from pigments that are found in plants including fruits, flowers and vegetables. Based on their chemical composition, natural plant-sourced pigments can be classified into structural groups including, but not limited to, anthocyanins, betalains, carotenoids, curcumin, carminic acid and derivatives, chlorophylls and their derivatives, etc. Carotenoids include, but are not limited to, β-carotene, α-carotene, apocarotenal, lycopene, bixin, norbixin, canthaxanthin, and zeaxanthin. Chlorophyll and chlorophyllin derivatives include, but are not limited to, copper complexes. In another non-limiting embodiment, the pigment may be complexed with a metal ion such as, but not limited to, copper.
One objective of the manufacturing industry is to concentrate the pigmented portion of plants to provide a more concentrated natural colorant that can be added to various food, drug, and cosmetic products. These concentrated colorants are produced by removing other compounds through separation processes.
Natural colorants are often recovered from fruit and vegetable juices which are high in sugar relative to the fraction of pigmented compounds. These sugar-based colors are typically concentrated to remove water and are used as a concentrate with greater than 60 percent sugar on a dry weight basis and low pigment levels. It will be appreciated that the concentrate may have higher or lower percentage sugar on a dry weight basis depending on the fruit or vegetable. Low color content liquids are expensive to store (often requiring refrigeration), are subject to degradation over time, have a high calorie to color contribution ratio in food or beverage applications due to high sugar content, and/or may impart undesired sensory characteristics.
The industry has provided two different forms of these natural colorants from fruit and vegetable juices, namely liquids and powders. Sugar-based colors are often difficult to dry and typically require a carrier such as maltodextrin or micro-crystalline cellulose to compensate for the hygroscopic character of the sugar.
Further, since the liquids that are subjected to drying are typically at about 50% w/w to 80% w/w water content, there are very few technologies available to efficiently dry such products. The most common technology available for drying liquids that have a low concentration of soluble solids is spray drying.
Unfortunately, spray drying has some disadvantages when it comes to handling of the dried product. Typical problems include, but are not limited to, significant deterioration of the product quality due to the high temperature and pressure that the liquid is subjected to during drying, the formation of amorphous particles with low bulk density due to the rapid rate of drying in micronized droplets, and poor water dissolution or wettability characteristics as well as hygroscopic tendencies due to the presence of sugars in an amorphous rather than crystalline state, making the powders prone to lumping or caking. Furthermore, successful spray drying of a fruit or vegetable concentrate with high sugar content typically requires the presence of a carrier, thereby weakening the color concentration and dosage efficiency of the finished product.
Another objective of the manufacturing industry is to substantially reduce the sugar fraction of the standard fruit- and vegetable-based color concentrates to produce a more concentrated natural color with lower caloric density that can also be dried to yield a product with improved storage and handling characteristics. Purified colors are typically produced by removing the non-pigment components of fruit and vegetable juices and extracts, thereby significantly enriching the material in the color compounds. Purified colors, containing low concentrations of sugar, can be dried using a broad range of drying processes including spray, drum, refractive window, and freeze driers. The present process provides combinations of purification and drying technology to produce concentrated natural color that can be dried without carriers. The concentrated natural colors described herein have a high color intensity and/or improved sensory, stability, and handling characteristics relative to other dry colors known to the industry.
The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.